This invention generally relates to a corner structure for trays, cartons, lids, and the like, and more particularly to a corner structure of the self-locking type.
Self-locking corner structures and other self-locking structures for use in cartons and the like are generally known. Examples are shown in U.S. Pat. Nos. 1,838,154; 2,307,720; 2,488,705; 3,902,653; 4,313,555; and 4,469,273. While these structures may be useful for their intended purposes, the self-locking corner structure of the present invention is believed to provide improved strength and ease of assembly resulting in a very secure structure without the use of additional materials or extra fasteners. Generally, this is accomplished in accordance with the present invention by the use of a fold over locking tab associated with one of the adjacent side panels which folds over a sloping edge of a flap associated with another adjacent side panel to lock the side panels in positions normal to each other and to the main panel. The entire structure is formed from a die-cut blank with means defining the various fold lines for the side panels, flap and tab.